So it is extremely important to get everyone mez'd that get's charmed. I believe this is the key to winning the event.

Additionally, much like Ghost, he spawns 3 adds at 90% and every 15% thereafter. The adds start out pretty weak, first wave was light blue (Enchanters check charm next time) they got progressively harder. Reported max hit was 2.2k, OT and kill these down, there is also quite a bit of room to kite these if healing is light.

Summary

Tank Snowtail, mez charmed people quickly, control adds. Win and move on to Sullon.

No fear, no doubt....All in, balls out

"Never doubt that a small group of committed people can change the world. Indeed, it is the only thing that ever has." Margaret Mead